Optical device



Dec. 26, 1939. w. GUNTHER 2,184,615

OPTICAL DEVICE Filed March 9, 1937 //7 ventor:

i-Y atented omcsr. DEVICE Woligang Gunther, Berlin-Friedman, =1

asdgnor to AMa-Werhe A. G., a ration Germany Application March 8, 198

i in Gm This -invention relates to an optical system which is moreparticularly adapted for use in, or in connection with, periscopes, i.e., instruments for obtaining a panoramic view or a part thereof.

One object of this invention is to provide an optical system forobtaining a wide range of vision, by unobstructed scanning in azimuthand.

elevation.

A further object is to provide for the afore- 1 mentioned purpose anoptical system having a minimum oi. reflecting elements, therebylimiting the loss of light intensity caused by each of such elements andobtaining a brighter image than it was heretofore possible.

" time.

Further aims, objects and advantages will appear from a consideration ofthe description which follows with the accompanying drawing showing anembodiment of the invention for illustrative purposes. It is to beunderstood,

% however, that the description is not to be taken in a limiting sense,the scope of the invention defined by the appended claims.

Referring to the drawing:

ms. 1 is a diagram illustrating the eiieot oi.

% inversion or inclination of the image in a periscope.

Hg is a sectional side elevation of a periscope embodying the invention.

Fig. 3 is a front elevation of the same instruso ment, partly insection. I

A simple periscopic instrument, consisting of two refiectingprisms Idand H is shown in Fig. i. The prim ii is stationary while the prism idis rotatable about an axis I-2 to permit a panoramic view. An object,represented in the drawing by an upright arrow, will appear upright intheprismil iithe'prism lBis i'acingtcthe leit. The arrow and thecorresponding position of the prism'are indicated in solid lines. Ii. eahowever, the prism as is turned about a vertical ems to view an uprightobject in a difierent Mmuthal direction the image will appear invertedor inclined. Fbr example, an object positinned at the right side of theinstrument apumde down in the lower prism H as is indicated by an arrowshown in dotted lines togather with the corresponding position of theprim id. It therefore appears, that an object which appears upright inone azimuthal position as of the rotatable prism will appear horizontala, rotation of the prism by 90 degrees, and upside down after a rm'ticnoi 180 degrees.

Itls common practice to commnsate for this"inciinationerrordbymeansofareflectingehmmt in w s' in thepath of light.As a ray of 1. sells! as. waste a less light reflected by an inclinedreflecting surface is deflected by te ms the angle of incidence, it isonly neomry to turn the said surface by half the amount of the rotatableor scanning prism to obtain a correct image.

if the scanning prism is inclined or tilted with respect to anhorizontal axis. b-d in order to scan objects below and above thehorizontal plane it will be noted that in an arrangement according toFig. 1 the view is limited. An obl0 iect. for instance, having anelevation oi about 90 degrees above the horizontal cannot be detectedwith the instrument. I therefore incline the path of light between thescanning and the scanning prism at an angle to its axis of azimuthalrotation, thereby obtaining an enlarged scanning range including thevertical, as will become further apparent from Figs. 2 and 3 showd0 ingin elevation at periscope embodying this inventions As shown in Figs. 2and 3 the scanning prism I9 is mounted in a prism-casing I? havingapertures i8 and id in plane. faced walls it and 16 n against which theprism i0 is resting under action of a plate ill provided with a spring II bearing against stops ll". The casing with the prism is tiltable abouta substantially horizontal axis 5-8 with respect to a second casing 18.Rear 80 walls is and 2d of both casings are curved concentrically to thetilting axis M leaving only a narrow space between the walls in order toprevent light or dust from entering the casings. The prism-casing isfurther provided with a. lid 2| 85 overlapping the rear and side wallsof the second casing and forming a pocket 22 with the walls of thepriamwasing into which the second casing projects. In a similar way thesecond casing id is provided with a pocket 23 oppositely to the sotilting axis 5-4 into which a curved wall or extension 26 of theprism-casing projects.

The prism id is tiltable in elevation by operating a handwheel 25driving a shaft 26 and a worm 2?. The gear 23 meshing with the worm 21turns the elevation shaft 29 to which the prism-casing is secured bymeans of flanges 3d.

The prism it? is rotatable in azimuth by p rating a second handwheel 8i,driving a worm and gear 32 and 3t, bevel gears 3d and 35 and a 60 pinion8S meshing with e. large gear 31 having teeth at the inside. The shaftoi the pinion is rotatably mounted in a bracket 88 secured to a standardorstationary housing 39. The housing is shown as supporting therotatable head, consisting of casings l2 and it, by means of a rollerbearing 40.

A reflecting element shown as being a mirror 4| with an externalreflecting surface is rotatably mounted about an axis parallel to orcoinciding with the azimuth axis I--2 within the stationary housing. Forthis purpose the mirror M is shown as supported by a frame 42 and thelatter mounted in trunnions 43 and 44 within a bracket 45 secured to thestationary housing. The upper arm of the bracket 45 is provided with asleeve secured thereto and bearing a fixed pinion M. The trunnion 43extends through said sleeve and bears an arm or web 48 secured theretoand provided with a pin 49 for rotatably supporting a gear so. The gear50 meshes with the stationary pinion 8? and the rotatable gear 37, thusforming a differential gear. It appears, that upon rotation of the headit, as in azimuth about a certain angle, the mirror 4| will be turnedabout half that angle.

There is further provided a reflecting member shown as being a prism Hfor deflecting the path of light into the objective of a suitabletelescope 52 for enlarging the image. Refracting elements of thetelescope are indicated by dotted lines. The telescope may be ofconventional construction and is shown as provided with the usualfocussing ring 53 and eyepiece 54.

The operation of the device is as follows. In the position shown in thedrawing the rays entering the scanning prism ID are reflected onto thereflecting surface ill and thence into the stationary-prism M and theobjective iii. The reflecting surface 4! permits an emission of raysfrom the scanning prism at an angle to the azimuth axis. In the positionshown the prism I0 is tilted for an observation of an object below thehorizontal,

34, but it may be tilted upwardly until the entering rays aresubstantially parallel with the azimuth axis. This feature thereforepermits an enlargement of the scanning range of the device. when thescanning prism is turned in azimuth the reflecting surface isautomatically turned about half the azimuth angle to compensate for theinclination error as hereinbefore explained. The reflecting surface 48thus serves a double purpose, namely inclination of the emitted rays ofthe scanning prism with regard to the azimuth axis, and further thecompensation of the inclination error. The advantage of providing onesingle element for this double purpose is a simplification of theoptical system by reducing the number of light consuming reflecting orretracting surfaces which results in a brighter image.

Obviously the present invention is not restricted to the embodimentherein shown and described. Changes may be made within the scope of theinvention for example by substituting reflecting mirrors for prisms andvice versa. Moreover, it is not indispensable that all the features ofthe invention be used conjointly, since they may be employedadvantageously in various combinations and subcombinations.

What is claimed is:

1. An optical device comprising, in combination, a substantiallyvertical housing; a supporting casing mounted on the upper end of thehousing for turning movement about a substantially vertical axis andhaving a portion ofiset laterally with respect to the housing; a firstreflector mounted in the offset portion of said casing for tiltingmovement about a substantially horizontal axis parallel with itsreflecting surface; means connected to tilt said reflector to directreflected rays downwardly into the casing at an angle to the vertical; asecond reflector compristng .a mirror mounted for turning movementwithin the housing at the opposite side from the offset portion of thecasing and substantially parallel with the turning axis of thesupporting casing and facing toward the first reflector to intercept andreflect the angular rays downwardly into the housing at a reflectedangle to the vertical; means for turning both of said reflectors in suchmanner that the second reflector turns about half the turning angle ofthe first reflector; and means to receive and direct the reflected raysfrom the housing.

2. An optical device comprising, in combination, a substantiallyvertical housing; a supporting casing mounted on the upper end of thehousing for turning movement about a vertical axis and having a portionoffset later-ally with respect to the housing; a first reflector mountedin the offset portion of said casing for tilting movement about ahorizontal axis parallel and spaced forwardly from its reflectingsurface; means con-,

nected to tilt said reflector to direct reflected rays downwardly intothe housing at an angle to the vertical; 8. second reflector comprisinga. plane mirror mounted for turning movement within the housing in theopposite side thereof from the offset portion of the supporting casingand connected for turning movement within the housing about a verticalaxis having its reflecting surface parallel with said turning axis andfacing toward the first reflector to intercept and reflect the angularrays into the lower portion of the housing at a reflected angle to thevertical; means for turning both of said reflectors in such manner thatthe second reflector turns about half the turning angle of the firstreflector; and means to receive and direct the reflected rays from thehousing.

3. A periscoplc instrument of the character described comprising, incombination, a substantially vertical stationary housing; a supportingcasing mounted on the upper end of the housing for turning movementabout a substantially vertical axis and having a portion offsetlaterally with respect to the vertical axis of the housing; a reflectingprism mounted in the ofiset portion of said casing for tilting movementabout a substantially horizontal axis parallel with and spaced forwardlyfrom the reflecting face of said prism;

' means connected to tilt said prism to deflect reflected raysdownwardly into the housing at an angle to the vertical; a secondreflector mounted for turning movement within the housing and having aplane reflecting first surface substantially parallel with the turningaxis of the supporting casing and facing toward the reflecting face ofthe prism to intercept and reflect the angular rays downwardly into thehousing at a reflected angle to the vertical; means for turning saidprism and said mirror in such manner that the mirror turns about halfthe turning angle of the prism; and means to receive and direct thereflected rays from thehousing.

WOLFGANG Gt'rN'rnnR.

